Dear Neha,
I am really sorry to hear that you are going through all this. but the sad part is, most of us allow this kind of behaviour from our partners and in-laws, and they continue to torture us like this for life.
it is a shame that you have to take permission from your husband to meet your parents. and the fact that he said you should not return again if you leave now should make you think of your relationship. is it really worth it? are you really so much in love with this man that you are willing to live like this forever? if yes, i can't say anything much. talk to him about your thoughts and see if he changes.
if you are willing to take a stand, be firm and tell your husband and in-laws that you do not need anyone's permission, and what they are doing is mental torture, and you will have to take legal action against them if they do not stop. if you are ready to face it, i would say take your baby and move out. stay with your parents if they support you. speak to a lawyer and yes, as soon as possible, start getting finacnially independent.